Question

Express the ratio 15:20 in its simplest form.

• A. 2 : 3
• B. 3 : 4
• C. 3 : 5
• D. 1 : 2

Answer 1

The correct option is B 3 : 4

In the simplest form, the numerator and denominator have no common factors other than 1.

We know,
15 = $3\times 5$
and
20 = $4\times 5$

We can write 15 : 20 as
$\frac{15}{20}$ = $\frac{(3\times 5)}{(4\times 5)}$
$\Rightarrow$ $\frac{3}{4}$
$\because$ 3 and 4 have no other common factors except 1, the simplest form of 15 : 20 is 3 : 4.